The schedule-induced ethanol polydipsia technique will be used with rats and monkeys to produce chronic physical dependence. Discriminative motor performance during acute and chronic intoxication, as well as in the abstinence state (ethanol withdrawal) will be evaluated. The alteration produced by physical dependence in the choice between ethanol and other desirable fluids will be ascertained. The effect of chronic physical dependence on ethanol upon the water-electrolyte balance of rats will be measured.